1. Field
Exemplary embodiments of the invention relate to a laminated structure and a vacuum insulating material using the laminated structure as an exterior material. More particularly, exemplary embodiments of the invention relate to a laminated structure and a vacuum insulating material being capable of effectively reducing a heat bridge, having improved workability, and suppressing generation of pinholes and cracks.
2. Description of the Related Art
A vacuum insulating material is obtained by vacuum-packaging a core material or a gas adsorption agent in a gas barrier exterior material, and suppressing thermal conduction by maintaining the inside thereof under vacuum. The vacuum insulating material has been used in an electrical product such as a freezer, a refrigerator, a warmer cabinet, and a vending machine, a house wall material, or the like since it has a low thermal conductivity.
The gas barrier exterior material used for maintaining a vacuum degree inside the vacuum insulating material consists of a laminate structure of an aluminum foil and a plastic, in order to prevent gas invasion from the outside. However, since the aluminum has high thermal conductivity of 237 Watts per meter-Kelvin (“W/m·K”), a vacuum insulating material using the laminate structure as an exterior material has a large heat bridge through which heat inflows from peripheral parts along an exterior material part.
In order to reduce the heat bridge of a vacuum insulating material, a laminate structure of an aluminum deposition layer and a plastic has been used in one direction of an exterior material (e.g., refer to Patent Reference 1). In addition, in order to reduce thermal conductivity while maintaining gas barrier properties, a vacuum insulating material using a metal foil having low thermal conductivity (e.g., iron, lead, tin, stainless steel, and the like) instead of an aluminum foil in a gas barrier layer has been suggested (e.g., refer to Patent Reference 2).
(Patent Reference 1) Japanese Laid-open Publication Sho 61-125577
(Patent Reference 2) Japanese Laid-open Publication Pyong 9-137889